Ever watch somebody repeatedly bang their head against a rock, the same rock, over and over again (this is metaphorical, of course) and think, "Ow, when is she/he going to feel enough pain to stop?" It's like watching one of those little wind-up toys that trundles around on the floor, runs into something, backs up a bit and changes course ever so slightly...and then slams into something again.
I've been one of the concussed, and I know the pain, but I've developed a pretty hightened awareness of when it's time to stop bashing into the same tree/rock/whatever and turn around and leave that obstacle in the dust. Sometimes the best way forward is back way up and pick another trail.
Unfortunately, some folks just don't seem to get it.